氯化钠组合叶蜡石合成金刚石的实验研究

人造金刚石的合成实验研究表明，在相同的合成工艺条件下，采用不同的叶蜡石做传压密封介质，合成金刚石的结果是不同的，其差异是明显的。这说明，叶蜡石的性质直接影响着金刚石合成，有时尤为显著。因此，了解研究叶蜡石的性质对超高压高温金刚石合成过程及其关系和其进行选择使用都是十分必要的。这个问题引起人们的关注。     

叶蜡石块加白云石内衬对金刚石合成的影响

讨论了在金刚石高压合成中，在传压介质叶蜡石腔体内加一层白云石内衬的作用，认为这种组合传压腔体可以降低合成压力，改善合成金刚石质量。     

急缺矿种金刚石合成固体密封传压介质叶蜡石资源开发研究及其对策

金刚石合成固体密封传压介质叶蜡石是一个急缺矿种,由于该资源的缺乏将会严重地阻碍我国超硬材料产业的发展。针对我国固体密封传压介质叶蜡石矿产资源的特点,提出了开发利用这种叶蜡石的措施和建议。     

急缺矿种金刚石合成固体密封传压介质叶蜡石资源开发研究及其对策

金刚石合成固体密封传压介质叶蜡石是一个急缺矿种,由于该资源的缺乏将会严重地阻碍我国超硬材料产业的发展.针对我国固体密封传压介质叶蜡石矿产资源的特点,提出了开发利用这种叶蜡石的措施和建议.     

叶蜡石传压介质资源初步研究

分析国内叶蜡石传压介质材料供需状况，指出北京赵家台叶蜡石传压介质材料资源枯竭，虽然国内叶蜡石矿石资源丰富，但适宜作叶蜡石传压介质材料资源却极少，急需从资源和材料特性着手，加大研究力度，寻找新的接替资源。     

传压介质立方块制备研究

通过对传压介质立方块制备工艺的研究，探讨了粒度及其配比、粘结剂、杂质矿物、焙烧温度和时间对合成金刚石效果的影响。     

合成金刚石生产中叶蜡石传压密封材料矿物学研究

叶蜡石是高温高压合成金刚石的关键辅助材料。叶蜡石传压密封材料的性能主要取决于叶蜡石矿石的矿物组成。叶蜡石矿石中的杂质矿物主要是一水硬铝石、明矾石、长石、高岭石、绢云母、绿泥石、石英、赤铁矿、钛铁矿、褐铁矿、金红石等。具有层状结构的矿物－水硬铝石、高岭石、绢云母、绿泥石等总量不超过10％，不会影响制品的传压性能。明矾石在高温高压下不稳定，是有害组分。长石、石英等非层状结构的矿物含量高时，会使叶蜡石传压密封材料静压流变特性变差，对传压性能是有害组分，应控制在小于5％，非常纯净的叶蜡石矿石制成的粉压块传压性能良好，但内摩擦系数小，密封性能差，常发生高压挤出和顶锤破坏现象，少量的赤铁矿、钛铁矿、褐铁矿、金红石矿物存在可以提高密封性能。     

叶蜡石矿产资源及其应用开发研究现状

介绍了叶蜡石在国内外的分布概况、叶蜡石的结构和特性，及其开发利用现状和存在的问题，并提出了相应的解决方法。着重分析了叶蜡石在超细粉体加工、表面改性、高温相变研究、涂料和填料中的应用，以及作为传压介质的研究现状；并在此基础上指出了其今后的发展方向。     

高强度粗颗粒金刚石的合成技术研究

在高温高压下,六方晶格的石墨转变为立方晶格的金刚石。选用灰分含量少、气孔分布均匀的T621A石墨为碳源,选择化学成分范围偏值小、杂质含量少的镍锰钴合金为触媒以及优质粉压叶腊石为传压介质,在高温、适压、长时间及其它条件下,合成高强度粗颗粒的优质金刚石取得了良好的效果。     

叶蜡石传压介质内衬材料的研究

分析了白云石或白云石 其它材料作为传压介质内衬材料的可能性，并通过对内衬材料的工艺设计阐述了它们合成金刚石的效果特征。     

同步辐射激光加温DAC技术及在地球深部物质研究中的应用

实验室模拟地球深部的温度和压力环境,研究地球相关材料的物理和化学性质,是解释地震波数据、进一步了解地球内部结构和动力学过程的重要途径。用高功率的红外激光光束,加温金刚石对顶砧压腔(DAC)中的样品,可以获得深部地幔乃至地核的极端温度和压力条件,已广泛地用于地球深部矿物的相变、熔融和状态方程研究。同步辐射微束技术的发展,为激光加温DAC技术的应用开辟了新的领域,也使地幔及地核条件下的矿物研究有了重要的突破。文章介绍激光加温DAC技术的发展;阐述高温高压原位的同步辐射X射线衍射方法;例举激光加温DAC技术在地球深部物质研究中的一些应用;并对一些关键的技术问题加以分析和讨论。     

金刚石中微量元素的同步辐射X射线荧光分析

利用同步辐射X射线荧光技术,对人工合成金刚石以及产自山东、辽宁、湖南的天然金刚石进行了微量元素的测试分析。结果表明,在合成金刚石中,检测到了第四周期的元素(除As、Ge、Kr和Br外)和Pb;其中Fe、Co、Ni相对含量高,可能是合成时触媒的混入引起的。天然金刚石中检测到的微量元素有Ca、Ti、Cr、Mn、Fe、Co、Ni、Cu、Zn、W、Au和Pb,但相对含量比合成金刚石中相应的微量元素相对含量低。不同产地的天然金刚石中的微量元素种类及含量存在差异,反映了金刚石地幔生长环境的不同及岩浆对金刚石生长过程的影响。     

Compressibility of nanocrystalline forsterite

We established an equation of state for nanocrystalline forsterite using multi-anvil press and diamond anvil cell. Comparative high-pressure and high-temperature experiments have been performed up to 9.6 GPa and 1,300°C. We found that nanocrystalline forsterite is more compressible than macro-powder forsterite. The bulk modulus of nanocrystalline forsterite is equal to 123.3 (±3.4) GPa whereas the bulk modulus of macro-powder forsterite is equal to 129.6 (±3.2) GPa. This difference is attributed to a weakening of the elastic properties of grain boundary and triple junction and their significant contribution in nanocrystalline sample compare to the bulk counterpart. The bulk modulus at zero pressure of forsterite grain boundary was determined to be 83.5 GPa.     

The age of high-pressure metasomatism in shear zones during collision-related metamorphism in the Lapland granulite belt: The Sm-Nd method of dating the paragenesises from sillimanite-orthopyroxene rocks of Por’ya Guba nappe

The Sm-Nd isotope-chronological method is used for the first time to investigate the whole rock and rock-forming minerals from metasomatic sillimanite orthopyroxene rocks in the Por’ya Guba nappe of the Lapland granulite belt. As a result isochrone values of the age are obtained, which allows estimate the minimum time intervals that have passed from the moment of formation of the investigated rocks. They indicate that peak conditions of collision metamorphism in fluid-permeable shear zones of the LGB occurred in the Paleoproterozoic Svekofennian age when high-temperature high-pressure sillimanite-orthopyroxene metasomatic rocks were formed. The obtained data make it possible to assume that, with regard to the measurement errors, high-pressure metasomatism did not last over 10 Ma, and this process did not coincide in time with older medium pressure metamorphism.     

不同类型彩色金刚石的谱学研究及其意义

对25颗不同类别的彩色金刚石进行了傅里叶显微红外光谱、紫外—可见—近红外吸收光谱、光致发光谱、拉曼光谱和X光荧光谱等谱学方法的研究。通过对近200张谱图的综合分析得到天然、合成、高温高压处理和人工辐射处理等彩色金刚石的特征谱,为金刚石类别的鉴定提供了标型,为研究彩色金刚石晶体缺陷引起的晶格畸变、晶格重组,以及色心的产生和消亡提供了新的证据。     

Fate of carbonates within oceanic plates subducted to the lower mantle, and a possible mechanism of diamond formation

We report on high-pressure and high-temperature experiments involving carbonates and silicates at 30–80 GPa and 1,600–3,200 K, corresponding to depths within the Earth of approximately 800–2,200 km. The experiments are intended to represent the decomposition process of carbonates contained within oceanic plates subducted into the lower mantle. In basaltic composition, CaCO₃ (calcite and aragonite), the major carbonate phase in marine sediments, is altered into MgCO₃ (magnesite) via reactions with Mg-bearing silicates under conditions that are 200–300°C colder than the mantle geotherm. With increasing temperature and pressure, the magnesite decomposes into an assemblage of CO₂ + perovskite via reactions with SiO₂. Magnesite is not the only host phase for subducted carbon—solid CO₂ also carries carbon in the lower mantle. Furthermore, CO₂ itself breaks down to diamond and oxygen under geotherm conditions over 70 GPa, which might imply a possible mechanism for diamond formation in the lower mantle.     

The strength of ruby from X-ray diffraction under non-hydrostatic compression to 68 GPa

Polycrystalline ruby (α-Al₂O₃:Cr³⁺), a widely used pressure calibrant in high-pressure experiments, was compressed to 68.1 GPa at room temperature under non-hydrostatic conditions in a diamond anvil cell. Angle-dispersive X-ray diffraction experiments in a radial geometry were conducted at beamline X17C of the National Synchrotron Light Source. The stress state of ruby at high pressure and room temperature was analyzed based on the measured lattice strain. The differential stress of ruby increases with pressure from ~3.4 % of the shear modulus at 18.5 GPa to ~6.5 % at 68.1 GPa. The polycrystalline ruby sample can support a maximum differential stress of ~16 GPa at 68.1 GPa under non-hydrostatic compression. The results of this study provide a better understanding of the mechanical properties of this important material for high-pressure science. From a synthesis of existing data for strong ceramic materials, we find that the high-pressure yield strength correlates well with the ambient pressure Vickers hardness.     

Raman spectroscopy at high pressure and high temperature. Phase transitions and thermodynamic properties of minerals

An outline of recent developments in Raman spectroscopy at high pressure, high temperature and combined high pressure and high temperature is presented. The instrumental and technical aspects of Raman spectroscopy, and coupling of diamond anvil cells and miniature furnaces to Raman microspectrometers are discussed. Some potential pitfalls, such as the thermal pressure in laser heated diamond anvil cells or the thermal radiation during high-temperature measurements, are presented. Special emphasis is given on processing of high-temperature Raman data. New recently discovered phase transformations in the SiO₂ system (quartz→ quartz II, pressure-induced amorphization of quartz) and structural changes in SiO₂ glass and melt are used to infer the capability of in-situ Raman spectroscopy for determining the microscopic behaviour of minerals, melts and glasses under extreme pressure and temperature conditions. Finally, it is shown how vibrational mode anharmonicity can be obtained from the pressure- and temperature-induced shifts of Raman modes. This anharmonicity can be introduced into the vibrational modeling of the thermodynamic properties (entropy and equation of state) of minerals. The example of calcite is briefly discussed.     

片、粉状触媒合成腔体内压力、温度的变化分析

对比分析了片状触媒合成体系和粉状触媒合成体系,在金刚石合成过程中,合成腔体内压力、温度的变化情况,并结合金刚石合成特征区分布图,分析辽些压力、温度变化对合成金刚石品质的影响,由此,指出粉状触媒是合成金刚石用触媒材料的较佳形态。     

A model for the origin of the cell-doubling phase transitions in clinopyroxene and body-centred anorthite

Comparisons of the structures of the high-pressure and high-temperature phases of both anorthite and clinopyroxene show that they are quite distinct although they share a common space group and site symmetries for all atoms. The low-pressure, low-temperature phases in both systems are formed by zone-boundary transitions from the high-pressure or high-temperature structures, and have structures that are made up of the alternation of portions of the high-pressure and high-temperature structures. This behaviour is analyzed in terms of the order parameter behaviour of the high-symmetry structures, and it is shown that the stability of the low-symmetry phases arises naturally from inhomogeneity in this order parameter.